Underreamer.



T. S. APGAR.

UNDERRBAMER.

APPLIOATION FILED 111111,14, 1913.

Patented Nov. 10, 1914.

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T. S. APGAR.

UNDERREAMER.

APPLIOATION FILED MAR.14,1913.

Patented Nov. 10, 191,4.

A SHEETS-SHEET 2.

l/WENTI? @aM/4.5 ifm/ ATTORNEYS w/mfssfs d. (Ca u rHE NDRRIS PETERS C0.. PHOT0-LITHO.. WASHING roNV D. C,

` wherein means is provided for automatically IY l N ITEI) STATES PATENT OFFICE. THOMAS S. APGAR, lOF ROBINSON, ILLINOIS, ASSIGNOR l0NE-FOUR'.T.T.-l TO ORLINv KIRK, ONE-FOURTH JIOv JOSEPH LORENZ, AND ONE-EIGHII-I TO GEORGERUSSELL,

ALL OF ROBINSON, ILLINOIS, AND ONE-EIGHTH TO DEAN E; PERI-IAM, OF

ILLINOIS.

CHICAGO,

UNDERREAMER.

Patented Nov. 1o, 1914..`

Appiieation mea March 14, 191e. seriai Nofrsasea .j

To all whom it may concern Be it known that I, THOMAS S. APGAR, a citizen of the United States, and a resident of Robinson, in the county of Crawford and State of Illinois, have invented a new and useful Improvement in Underreamers, of which'the following is a specification.r

My invention is an improvement in under-reamers, and has for its obj ect to provide a tool of the character specied, especially adapted for under-reaming well casings, as for instance, in gas, oil or other wells, 'wherein the reaming mechanism may be contracted within a diameter less than that of the interior of the well casing to permit the passage .of the tool through the casing, and

expanding the reaming mechanism when the proper position is reached, and wherein the parts may be again contracted to permit the removal of the tool from the casing.

In thedrawings z-Figure 1 is a longitudi-v nal section of the improved under-reainer, with the bits in contracted position, Fig. 2 is alongitudinal section at right angles to Fig. 1, Fig. 3 is a section on the same plane as Fig. 1, with the bits expanded, Fig. l is a section on the same plane as Fig. 2, with the bits expanded, Fig. 5 is a perspective view of the under-reamer, Fig. 6 is` a per-- spective view of the internal parts in separated position, Fig. 7 is a perspective view of theexpanding wedges and their supports,v Fig. 8 is a perspective view of the bits andv their support, Figs. 9, 10 and 11v are sections on the lines 9-9, 10-10 and 1p1-11 respectively of Fig. 1, and Figs. 12`and 13 are sections on the lines 12-12 and 13-18 respectively of Fig. 3.

The present embodiment of the invention comprises a tubular casing 1, lia-ving oppositely arranged longitudinally extending slots 2, intermediate its ends, and a head is connected with the upper end of the casing.

The said head comprisesa 'bodyw3, rectangup lar in cross section, having-atits ends integral disk flanges 4 and 5 respectively.`

The head is provided at the flange l with a threaded stem 6, and at the yflange 5 with a cylindrical lug 7, which is received within the upper end of the casing 1, and is secured thereto by means of the cross pin The stem 6 is adapted to engage the hoisting and lowering mechanism for the tool, and the rectangular body 3 is adapted to be engaged by a wrench or the like, to attach the tool to the said hoisting and lowering mechanism. The flange 5 of the head "fits 'against and closes the upper end of the casing.

A tubular dog support '9 is 1 arranged with-k in the casing, adjacentfto the head, the said support having a transverse opening 10, near its upper end, which is engaged by a pin 11, passing through the supportand the casing, to hold the said support in position. fThe support is provided with longitudinally extending oppositely arranged similar arms 12, at its lower end, and the space between the arm at each side of the said support is approximately'key-hole shape, to receive the keys shown in Fig. 6, each of said keys coin-` prising a head 13, and a stein 14. The said vkeys fit withinthe said spaces, and the operating dogs 15 fit vagainst the keys. Each Vof the said dogs is provided at each end on its inner side `edge with a cross head 16, and the arms l12 of the dog support are notched as indicated at 17, to receive the said cross heads to prevent vertical movement of the dogs when they are so engaged. It will be noticed that the lower end of each of the keys 13-14 is beveled on its inner face as shown at 18.

LThe bit support 19, shown in detailkin4 grooves for re-v iny Fig. 8, the bits may be engaged vwith the,

support'19, by introducing them from the y lower end of the support. The groove 2O is of suiiicient width to permit the passage of the lugsk 23, and the reduced portion of the groove 2O has a passage 25, connecting the lower end of the groove with the adjacent grooves 20 are of greater recess 24. The depth than thejthickness of the bits, vand the passage 25 is' at the bottom of the grooves, so that after the lugs 23 have'passed through the passages 25 and into register with the recess 24,A an outward movement of the bit will engage the lugs 23 with the said recesses to prevent downward movement of the bits with respect to the support. At opposite sides of the bit, shoulders are formed between the main portion and the neck, and each of the said shoulders consistsV of two oppositely beveled portions 26 and 26l respectively., Atthe lower end of the reduced portion of the grooves 20 beveled shoulders 27 are formed, for engagement by the shoulders 2(3*262 The arrangement of the said shouldersy 26---26a permits some rocking movement of the bit on the shoulders 27. The support is also provided with an upwardly extending lug 28. It will be noted that when the bits are in place on the support and in inward position the rounded outer surface of the bits is uniform with the rounded outer surface of the support to form a substantially cylindrical body.

The spreading wedges 29 are arranged be tween thebits and the support, each wedge having an upwardly extending stem 30, provided at its upper end with a transverse opening 31. Each of the wedges 29 has an extension 32 connecting the said wedge with its stem, and the outer facey of each extension is rabbeted at each side edge as in dicated at 33. The width of the rabbet is approximately the width of the passage 25, so that the rabbeted edge ofeach wedge extension moves within the said passage, while the lower end of the rabbet forms a stop for limiting the upward movement of the wedge. Each wedge is also provided with a transverse opening 34, at its lower end for a purpose, to be presently described. A wedge support 35 is provided, the said support having oppositely arranged notches or recesses 36 at its lower end for receiving the upper ends of the stems 30, and the support is provided with an opening 37 at the said recesses for registering with the openings 31 of the stems, and a headed pin 3S is passed through the registering openings 31-37 to connect the stems to the wedge support. The upper end of the wedge support is also recessed on opposite faces, as indicated at 39, and the said recesses arebetween the recesses 36, or at right angles to the said recesses.

The support is provided with an upward extension 40 at its upper end and the upper end of the extension is reduced as indicated ends 18 of the said keys lit against the bev` eled shoulders 43 at the junction of the reduced portion with the main portion.

A coil spring 44 encircles the stems 30 between the upper end of the lug 28 of the bit support and the lower end of the wedge support. The dogs l5 are arranged within the slots 2 of the tubular casing and the said dogs move in the said slots, the slots being of approximately double the length of the dogs. Y

In the use of the tool, when it is desired to introduce the same into the well casing 45, the wedges are drawn down until they extend below the lower end of the bit support as V4indicated in Figs. 1 and 2. The bits swing inward as shown in the said figures until their outer surface is flush with the outer surface of the tubular casing. The dogs 15 are at the vupper ends of the slots 2, the cross heads 16 thereof being received within the notches 17 of the dog support 9. The reduced portion 41 of the wedge support is received between the stems 14 of the keys 13-14, and the coil spring 44 is compressed. p

The wedge support 35 cannot move upward because of the engagement of the end 42 thereof with the heads 13 of the keys and because of the engagement'of the shoulders 43 thereof with the beveled ends 18 of the stems of the keys. The heads 13 of the keys have their inner surfaces in contact, thus closing the opening 46 at the lower end of the tubular portion of the dog support and as long as the dogs 15 are in this position, the keys are so held to prevent upward movement of the wedge support. After the tool has passed below the lower end of the well casing 45, the spring 44 will expand and will move the wedges and the wedge support upward. The shoulders 43 of the said support will spread the lower ends of the keys 13-14 apart, pushing out the lower ends of the dogs and pushing out the cross head 16 at the said lower end from the adjacent recess 17.

The end 42 of the support will spread the vheads of the keys and push out the upper ends of the dogs, disengaging the cross heads at the said ends from the upper notches 17, and the reduced end 41 will pass through the opening 46 into the interior of the dog support. The dogs 15 now occupy the position of Fig. 3, and the bits 21 are expanded. It will be noticed that each bit is beveled at its lower end from within outward to form a cutting edge at the outer e corner of the lower end, and when the tool is operated in the usual` manner, the said edges will ream out the soil below the end of the casing las indicated in Fig. 3 to perkwhen the tool, is vdrawn lupward '-,ashOr't y'dise' tance farther, the kdogs will be-pushedfdown-J ward, drawing. down other support `lV and compressing. the spring, 444': It'. will'be 'noted that the upper outer 'corrieri of each. dog @15 is slightly. beveled as-shownat 47,( and asi soon `as the dogshave rea'ohed'thelower yendsof the slots 2, the farther upward movement of the tool will push-in theiupp'er ends'of .the

dogs, moving. .the key'f heads 113 into' fcontaotv port is atv this time ini suoh'iposition thatthe lower endsl of the keys may moveinwardlyf and as thel dogs 15 move entirely 'into theA well casing, thekeys again'takertheposition' of Fig. l, thus looking the wedges in lowered position.

The wedges remain in the lowered position after the tool is withdrawn at yth'eitopfoffthe"l casing. When y*it is desired to' rente'rrwthe" reanier in the' casing, a ksinall roduis inserted in the lower exposedportionsof thefwedgesgf and a small wedge orflever isplac'ed between the said rodandthe bottom offthe '-casin'gl,y

to release the tension of the /springilr 'Ihey dogs l5 are thus released, f'andftheyffaremoved to the top: of the slots2, and pushed into thecasin'g, as shownrin llig'.y l. A'-ring14 or like element is placed overthefcasing l,

at the dogs l5, to hold theniini plaoeinfth'eir inward position. The tool `is now entered at the upper end of the well easing, and isv permitted to move into'lthe casing,.until the lower ends of the dogs -15 are engaged by the casing. The casing ynow holds the ldogsin inward position, and the ringwmay bey withdrawn. As soon as they dogspass below the `lower end of the' well easing, they 'move outward, andy thel wedge support 35 is released, and the wedges move upward, forc` ing the bits into the working position; hen tlietool is raised to bring the dogs 15 into contaotwith the' lower end of thecas-y ing, ythe dogs are forced downward to the lower endsof the slots 2,fand then inward into the casing, so that they may 'moveup-'l ward through the well easing. lt will be noticed that the wedges' have openings 34; for engagement by a tool'in order that they may be pulled downward into the 'position of Fig. 1. f f

`Wlien the dogs l5 are drawn downwardly in the slots 2, by their engagementwith the lower end of the well casing,-the wedges and the wedge support are moved downward with the dogs. The keys, however, by reason of the engagement of their rounded heads with the rounded openings of the dog `support 9, cannot move downwardbeing held by the dog support 9 in the position shown in Figs. 1 and 3 of the drawings. As soon as the shoulders 43 pass below the lower ends of the keys, the dogs move inward. There is suioient room (for the dogs between the cam extension 42 of the wedge supports andfftheff-periphery:sofftheftubulareasing-s1, i

andthe-@inward movementtof thedogsforces! of the dogesupport receive "the"l cross f' heads'- 16 of the rdo'ggristo .pei-mib; ,the Said .dogsxtd i move ffar fenouughinwardly lto'" bring ltheirf I, outer edges'uslr with* the periphery". off the'f tubular `"support wheninf this position,l and they lare so yheld their` engagement with f lthe well casing, the said dogs" cannot movel downwardly: foril the dog'- siipportf'is; fixed with? 'respecttol'theiftubular casing/ The outward.

provided"intheftubular easing 1 fat 4a 'point' registerwithflthe said openingstopermitfthe 1 removalf offthetpinf to detachthe jwedges' from" the'1 wedge'f` support, toE permit'- thelrel kmova'l of fthe S wedges- When "the wedges havefbeenremoved by simply withdrawing f ed to the'fwedge'isupportby thewdgesj 1 It' will'be'1evident @from an inspection: of

1 andfthe :bit support'andL theE bits lare co'nnect-l t "'95 "g `Fig.3 '-tliatcthe-bitf supportcould not move f. downward lwi'th'frespeet "t'o-Y the 'wedges/bef cause the l' bits cannot 'be''any further'extendi ed at their upp'erendsand thewe'dg'es yare" of too great thickness to? pass betweenv the* upper ends 1 of the* bits 'and-1. the* bitfy supp'ort.

No otherfconne'ction is necessary between the bit,the"bit supportandtliewedge supporti Iclaim'- f Y l. The' combination with arr underereamer oomp'risingY a tubular casing provided 'f at vits upper end lwith oppos'itelyA arranged longii tudinally extending slots, andat its'lower end with bitsmoun'ted to swing beyond the -V i periphery ofi` thecasing `into vworking f position, wedges movable longitudinally of the casing forexten'dingthe bits`, a wedge sup`- port-to which the wedges arefconnected, 'and ajspring acting normallyto movev the wedge fii5- support'in aldirection' to cause vthe wedges to extend the bits, of means for holding ther wedges `in inoperative position against the resistance? offft'he sp'ring,' said means comprisingdogs slidablfe `inthe slots'lo'ngi'tudinally f of the casing and movable radially withre- .spectf thereto,` the wedge support *havingf iso y Wedge support to extendthe bits, a dog support rigid with the casing andhaving a bore for receiving the cam extensionand havingradial openings fromthe bore at the dogs, keysin the openings ofl the dogsupport, the lower ends `of the keys beingbeveled for engagement by the' cam extension and 'said keys-engaginglthe dogs,the .dogs having crossheads extending' across the openings for the keys of the dog support to limit thel inward movement vof the dogs.` `1

2. The combination with an under-reamer comprising a tubular casing provided at its upper end with oppositely arranged longitudinally extending slots, and at its lower end with bits mounted to swing beyond the periphery vof the casing into working osition, wedges movable longitudinally o the casing for extending the bits, a wedge support to which the wedges are connected, and a spring acting.normally to move the wedge support in a directionto cause the wedges to extend the bits, of means for holding the wedge support from ,upward movement, said means comprising dogs in thel slots movable longitudinallyl and ra dially of the-casing, the wedgesupport having ya cam extension moving between the dogs to move them outward beyond the periphery of the casing, the dogs preventing upward movement of thesaid support when in position within the periphery of the tubular casing, a dog support rigid with the casing at the slot and havingy a bore for receiving-the cam extension and having radial openings at the dogs, keysv within the openings movable radially of thefdog support and having means for engaging the support to prevent longitudinal movementv thereof, the dogs having cross heads extending across the openings for the keys, and the extension engaging the keys to move the dogs outward, the wedge support having shoulders for engagement by the lower ends of the dogs when the dogs are moved downwardly in the slots to cause the said wedge support to move with the dogs, and the slots being of suflicient length to permit the lower ends of the dogs to move below the dog support to permit them to move inwardly when at the lower ends of the slots.

3. The combination with an under-reamer comprising a tubular casingprovided at its upper end with oppositely arranged longi tudinallyextending slots, `and at its lower end withbits mounted to swing beyond the periphery of the casing into working position," wedges movable longitudinally of the casing for extending the bits, a wedge support to which the wedges are connected, and a spring acting normally to move the wedge support in a direction to cause the wedges to extend-'the bits, of means for holding the wedge support against theresistance of the spring, said means `comprising dogsvmount` ed. for longitudinal sliding movement of the slots and forradial movement with respect to the tubular casing, the wedge support having a cam extension' moving be- -tween the dogs and extending them beyond `upper end with oppositely arranged longitudinally extending-slots, and at its lower end with bits mounted to swing beyond the periphery of the casing. into working position, means movable longitudinally of the casing for extending the bits, and a spring normally` acting to move the said means in a direction to extend the bits, of means for holding the said expanding means against fthef'resistance lof the spring, said holding means` comprising dogs mounted for longitudinal sliding movement in the slots and for radial movement with respect to the casing, a cam connected with the expanding means and moving between the dogs to extend them beyond the periphery of the casing, when the expandingmeans moves upward to expand the bits,'a dog support rigid with the casing at the slots and having means for engagement by the dogs when Vwithinthe periphery of the tubular casing,

to lock the dogs at either end of the slots with the spring under compression.

, THOMAS S. APGAR.

Witnesses: GEORGE M. RUSSELL, JABAL D. 'BANDY.

Copies of this patent may be obtained forve cents each, 'by addressing the Commissioner of Patents,

'Washington,D.C. v 

